Intercropping of sesbania (Sesbania sesban) and leucaena (Leucaena leucocephala) with five annual grasses under semi-arid conditions as affected by inoculation with specific rhizobia and associative diazotrophs

Overview & Synopsis

Intercropping of legumes and non-legumes is considered to improve the quality and quantity of field forage crops. Under semi-arid desert conditions, intercropping of leucaena and sesbania with some annual grasses (barley, pearl millet, and Rhodes-, rye- and sudan-grasses) was evaluated in a series of field trials. Inocula of specific rhizobia for legumes and a composite of associative diazotrophs for non-legumes were applied in the presence or absence of N fertilizers. Rhizobia inoculation was indispensable, and supported better growth of legumes which extended to the neighboring non-legumes. Associative diazotrophs improved biomass and N yields of non-legumes, particularly in the presence of moderate N fertilization for winter barley and rye grass and of higher doses of 300 kg N$\cdot$ha$^{-1}$ for summer pearl millet and sudan grass. Intercropping improved productivity of non-legumes, in particular barley mixed with sesbania, and the calculated N-transfer from legumes to non-legumes ranged from 20 to 70 kg N$\cdot$ha$^{-1}$.